Fresh from his cameo gig on the TV series Gossip Girl, where he played a famous writer who worked in dusty bars with a glass of whisky to hand, temporary mentor to an aspiring teenage littérateur, Jay McInerney is back in print with a collection of short stories. Just as the one-time enfant terrible's appearance on the show represented an explicit passing of the cultural baton labelled "cutting-edge, hip, young Manhattan", so his new book confirms McInerney's contemporary market niche as that of a kindlier, more palatable alternative to Bret Easton Ellis, who remains too dangerous for the mainstream.

These are stories of sex and money set in and around New York City, where gentle satire and situation comedy give way to dark epiphanies about doomed marriages or social failure. There are references to Catholicism, and a general lack, among the non-Catholic characters, of anything to believe in. As one woman is given rather blandly to think, in the wake of 9/11: "Though she wished she had some kind of faith, after what had happened she was hard-pressed to imagine a moral order in the universe."

Never mind; McInerney will imagine it for you. In these stories, wrongs are poetically punished. Adultery is a frequent premise, and spouses find ingeniously subtle ways to avenge the sin - demanding that a favourite cat be taken to be killed at the vet's, or persuading a partner to take up troilism. One story is about a gold-digger among the Upper East Side rich, whose plan to ensnare a wealthy entrepreneur goes wrong, causing the door of "society" to slam abruptly in her face. Another is about a writing teacher whose girlfriend plans a surprise birthday party for him: since he doesn't notice anything suspicious, she decides he can't be a good writer and snogs the restaurant owner instead. In short, these are morality tales, almost all of which end with the realisation that a kind of satisfyingly neat, if faintly perverse, justice has been done. Taken one at a time, they are finely shaped, but in sequence the sound of traps springing shut becomes repetitive and predictable.

Even so, one is drawn headlong into the next story, because McInerney is particularly brilliant at beginnings. Several opening sentences succeed in creating an entire distinct voice and comic tone. One begins: "So I come in the front door about one in the morning, after stopping to get some beer and cigarettes, and I hear these sounds from the living room." The combination of idiomatic syntax and carefully withheld information makes for an instant hook: you imagine you are about to be told a shaggy-dog story by a brilliant barfly raconteur. The same trick is performed in another opener: "Everyone imagines it's all about blow jobs, or esoteric skills practised in the more exclusive brothels of Europe and Asia." Hang on - everyone imagines what is about blow jobs? The reader instantly needs to find out.

The prose throughout is of the kind that looks casual but is unimpeachably crafted. As usual, McInerney is very funny, dropping in delicious shards of literary cynicism - "His first play revolved around the death of a mother from cancer. There seemed to be a number of those that particular season, but his was the most successful" - or demonstrating perfect comic timing within a sentence, as when he describes one hell-raising character "marrying, spawning and divorcing; wrecking cars and discharging firearms at inappropriate targets, including, finally, himself".

Consequently, the two stories here that rise above the formulaic are those where the writing is most free to breathe, where the ending is not the crack of a moralist's gavel but something more like the soft thunk of a well-engineered car door. In "Penelope on the Pond", the narrator is the secret lover of a politician running for office: while McInerney pokes gentle fun at her new-agey beliefs, it is a surprisingly sympathetic portrait, and the politician's final abandonment of her is all the more devastating for existing nowhere but between the lines. The title story, meanwhile, manages by the end to evoke something very like the Scott Fitzgerald-ish troubled wistfulness to which it aspires.

In one of these stories, a man driving to his mistress's house feels a "welcome sense of moral clarity". The sardonic choice of words here shows that McInerney's instincts are right. "Moral clarity" is the domain not of literature but of superficial pundits. The least successful stories in The Last Bachelor are those illumined by the cheap fluorescence of "moral clarity"; but there is something more going on in the murky depths of the best.